1. Field of the Invention
The present invention relates to an optical recording medium comprising a plurality of information layers which are placed between a substrate and an optically transparent cover layer with optically transparent spacer layer interposed between the information layers.
2. Description of the Related Art
Optical recording media, such as CDs (Compact Disc) and DVDs (Digital Versatile Disc), have been widely utilized as information recording media. Furthermore, in recent years optical recording media with even higher densities that can record large quantities of information by means of using blue or blue-violet laser light as the irradiation light have been gathering attention. Moreover, these optical recording media can increase the recording capacity to that extent by providing a configuration comprising a plurality of information layers which are placed between a substrate and an optically transparent cover layer with optically transparent spacer layer interposed between the information layers (for example, see Japanese Patent Laid-Open Publication No. 2003-338082).
There were trends, however, in which the exactness of reproduction of the data on the optical recording medium became low due to this type of configuration comprising a plurality of information layers.